The present invention relates generally to the field of energy conservation and more particularly to a supplemental ducting system operating in combination with a conventional forced air delivery heating and cooling system.
Such conventional forced air heating and cooling systems generally comprise a heating and cooling unit which contains, for example, a coil through which, depending upon the season, hot or cold fluid is circulated. Simultaneously air which is to be heated or cooled prior to delivery to the thermally controlled space is forced over the outer surface of the coil. External fins frequently are used to extend the heat transfer surface of the coil in the known manner. In some systems the heating and cooling elements may be separate and operate independently one from the other. The heating unit may comprise a fossil fuel combustion chamber or electrical heating elements, whereas cooling may be accomplished using a coil with two phase evaporating refrigerant circulated therein. Further the heating-cooling unit may be one coil of a heat pump refrigeration cycle wherein said coil serves alternately as a condenser for heating purposes and as an evaporator for cooling.
The air which has been heated or cooled is then distributed throughout the building through a duct network which extends in many branches from the heating or cooling unit to wall, ceiling or floor outlets in the controlled spaces. Return ducts carry air from the temperature controlled spaces back to the heating-cooling unit for reconditioning and recirculation.
These systems may also draw in a portion of air from the external ambient for ventilation purposes, and this inflow adds to the heating or cooling load. However, all of these conventional systems neglect to use the natural thermal energy source for heating and the natural heat sink for cooling which exist in many buildings and residences.
Specifically in the summer the air temperature in the building basement is usually significantly lower than either the external ambient air or the general internal living space temperatures of the building. This favorable basement temperature results from the soil around the foundation walls which remains relatively cool even in the summertime and substantially isolates the basement ambient from rapid temperature changes. In the winter, the air in the attic is heated above the external ambient temperature by the incidence of solar energy on the roof.
Use of these natural reservoirs reduces the thermal load requirements on the heating and cooling systems and as a result effects reductions in consumption of input source energy. What is needed to improve the overall efficiency of residential environmental control is a system which supplements the conventional heating and cooling units by tapping the natural thermal reservoirs available in the home because of the nature of the building construction.